215 research outputs found
Understanding Child Feeding Practices of Vietnamese Mothers
Purpose: To understand the feeding practices, knowledge, and nutritional beliefs of Vietnamese mothers with young children who are recent immigrants to the United States
Performance Characteristics of Indigenous Turkeys Fed Indomie Waste Based Diets
. This study evaluated the performance of Turkey poults fed indomie waste based diet. A total of ninety six (96) local strain Turkey poults were allotted to four dietary treatment in which indomie waste was used to replace maize at 0, 33.33, 66.67 and 100% levels, representing one to four treatments respectively. Each treatment was replicated three times with eight poults per replicate. The study which lasted for eight weeks was a completely randomized design experiment. Results showed that indomie waste significantly increased the average weight gain and improved feed conversion ratio. The cost of feed per kg decreased with increasing levels of indomie waste in the diet. The lowest cost was obtained at 66.67% inclusion level. It was evident that indomie waste could be incorporated into the diet of local strain Turkey poults up to 66.67% level without any deleterious effect on the performance of the Turkeys. There is also a concomitant reduction in feed cost per kg weight gain
Risk Behaviors of Dominican Adolescents in Their Homeland and in the United States
The purpose of this study was to compare self-reported high risk behaviors that may lead to unintentional and intentional injuries among adolescents living in the Dominican Republic and Dominican adolescents living in the United States
Casimir forces from a loop integral formulation
We reformulate the Casimir force in the presence of a non-trivial background.
The force may be written in terms of loop variables, the loop being a curve
around the scattering sites. A natural path ordering of exponentials take place
when a particular representation of the scattering centres is given. The basic
object to be evaluated is a reduced (or abbreviated) classical pseudo-action
that can be operator valued.Comment: references added, text clarified in place
Space-time dependent couplings in N=1 SUSY gauge theories: Anomalies and Central Functions
We consider N=1 supersymmetric gauge theories in which the couplings are
allowed to be space-time dependent functions. Both the gauge and the
superpotential couplings become chiral superfields. As has recently been shown,
a new topological anomaly appears in models with space-time dependent gauge
coupling. Here we show how this anomaly may be used to derive the NSVZ beta
function in a particular, well-determined renormalisation scheme, both without
and with chiral matter. Moreover we extend the topological anomaly analysis to
theories coupled to a classical curved superspace background, and use it to
derive an all-order expression for the central charge c, the coefficient of the
Weyl tensor squared contribution to the conformal anomaly. We also comment on
the implications of our results for the central charge a expected to be of
relevance for a four-dimensional C-theorem.Comment: 28 pages, LaTeX, no figure
Integrable Open Spin Chains in Defect Conformal Field Theory
We demonstrate that the one-loop dilatation generator for the scalar sector
of a certain perturbation of N=4 Super Yang-Mills with fundamentals is the
Hamiltonian of an integrable spin chain with open boundary conditions. The
theory is a supersymmetric defect conformal field theory (dCFT) with the
fundamentals in hypermultiplets confined to a codimension one defect. We obtain
a K-matrix satisfying a suitably generalized form of the boundary Yang-Baxter
equation, study the Bethe ansatz equations and demonstrate how Dirichlet and
Neumann boundary conditions arise in field theory, and match to existing
results in the plane wave limit.Comment: 26 pages, LaTeX. v2: references added, typos correcte
Mesons from global Anti-de Sitter space
In the context of gauge/gravity duality, we study both probe D7-- and probe
D5--branes in global Anti-de Sitter space. The dual field theory is N=4 theory
on R x S^3 with added flavour. The branes undergo a geometrical phase
transition in this geometry as function of the bare quark mass m_q in units of
1/R with R the S^3 radius. The meson spectra are obtained from fluctuations of
the brane probes. First, we study them numerically for finite quark mass
through the phase transition. Moreover, at zero quark mass we calculate the
meson spectra analytically both in supergravity and in free field theory on R x
S^3 and find that the results match: For the chiral primaries, the lowest level
is given by the zero point energy or by the scaling dimension of the operator
corresponding to the fluctuations, respectively. The higher levels are
equidistant. Similar results apply to the descendents. Our results confirm the
physical interpretation that the mesons cannot pair-produce any further when
their zero-point energy exceeds their binding energy.Comment: 43 pages, 8 figures, references edited, few typos corrected, updated
to match the published versio
Supersymmetric probes on the conifold
We study the supersymmetric embeddings of different D-brane probes in the
AdS_5 x T^{1,1} geometry. The main tool employed is kappa symmetry and the
cases studied include D3-, D5- and D7-branes. We find a family of three-cycles
of the T^{1,1} space over which a D3-brane can be wrapped supersymmetrically
and we determine the field content of the corresponding gauge theory duals.
Supersymmetric configurations of D5-branes wrapping a two-cycle and of
spacetime filling D7-branes are also found. The configurations in which the
entire T^{1,1} space is wrapped by a D5-brane (baryon vertex) and a D7-brane
are also studied. Some other embeddings which break supersymmetry but are
nevertheless stable are also determined.Comment: 44 pages, LaTeX; v2: typos corrected, references added, discussion of
D5-brane embeddings improve
Dynamics of Fundamental Matter in N=2* Yang-Mills Theory
We study the dynamics of quenched fundamental matter in
supersymmetric large SU(N) Yang-Mills theory at zero temperature. Our tools
for this study are probe D7-branes in the holographically dual
Pilch-Warner gravitational background. Previous work using
D3-brane probes of this geometry has shown that it captures the physics of a
special slice of the Coulomb branch moduli space of the gauge theory, where the
constituent D3-branes form a dense one dimensional locus known as the
enhancon, located deep in the infrared. Our present work shows how this physics
is supplemented by the physics of dynamical flavours, revealed by the D7-branes
embeddings we find. The Pilch-Warner background introduces new divergences into
the D7-branes free energy, which we are able to remove with a single
counterterm. We find a family of D7-brane embeddings in the geometry and
discuss their properties. We study the physics of the quark condensate,
constituent quark mass, and part of the meson spectrum. Notably, there is a
special zero mass embedding that ends on the enhancon, which shows that while
the geometry acts repulsively on the D7-branes, it does not do so in a way that
produces spontaneous chiral symmetry breaking.Comment: 24 pages, 8 figures. Corrected typos, added comment about
counterterm. To appear in JHE
Weak coupling large-N transitions at finite baryon density
We study thermodynamics of free SU(N) gauge theory with a large number of
colours and flavours on a three-sphere, in the presence of a baryon number
chemical potential. Reducing the system to a holomorphic large-N matrix
integral, paying specific attention to theories with scalar flavours (squarks),
we identify novel third-order deconfining phase transitions as a function of
the chemical potential. These transitions in the complex large-N saddle point
configurations are interpreted as "melting" of baryons into (s)quarks. They are
triggered by the exponentially large (~ exp(N)) degeneracy of light baryon-like
states, which include ordinary baryons, adjoint-baryons and baryons made from
different spherical harmonics of flavour fields on the three-sphere. The phase
diagram of theories with scalar flavours terminates at a phase boundary where
baryon number diverges, representing the onset of Bose condensation of squarks.Comment: 38 pages, 7 figure
- âŠ